The present invention relates to a motion control apparatus for an induction motor and, more particularly, to a motion control apparatus for an induction motor which utilizes slip speed to suppress excessively quick acceleration and deceleration of the induction motor.
Induction motors have been widely used in various applications as constant speed motor or as constant frequency power sources by utilizing their inherent rigid structure, low cost, and the like.
However, the induction motor has not been used as a servo motor because it cannot provide quick acceleration and deceleration.
Due to recent improvements of electronic devices, microcomputers, and software techniques, a vector control technique that can change the frequency of a power source for driving the induction motor over a wide range is realized, and the induction motor itself is also improved. As a result, the induction motor may be used as the servo motor.
Such a variable frequency power source is operated by a vector control process described in, e.g., "New Drive Electronis", written by Naohiko Kamiyama, Denki Shoin (to be referred to as Literature 1 hereinafter).
The aforementioned Literature 1 includes a section which will said in the understanding of the present invention and which essentially reads as follows.